The ideas conceming 'the nature of life' are fundamental to our understanding of all biological aspects of science. However; while 'life' might appear at a surface level to be a straightfotward concept to define, the closer you look, the more involved it becomes. This section attempts to provide clear scientific (as opposed to dictionary) definitions by which to classify life. One of the key problems with developing conceptual understanding in this area is the need to remember both common usage and scientific definitions of terms, and to know when to use each. The key ideas to be developed here are:
I . Life processes, common to ail living things, can be used as a means of defining life.
2. Everything can be divided into 'living', 'no ionger living' and 'never lived',
3. Living things can be arranged into a broad classification system involving five kingdoms.
Teaching Concepts
Click on each concept to see Subject facts, Why you need to know these, Vocabulary, Amazing facts, Common misconceptions, Questions and Teaching Ideas
It is important to be aware of how these concepts af life might be developed Below, you can follow one way in which this progression can be traced. It goes up to Key Stage 3 because it is necessary to know where the children will be going next. A useful way to demonstrate your own understanding of the concepts is to produce your own concept chain.
All living things, including human children, share a set of common characteristics Animals are a type of living thing. Humans are a type of animal. All animals have the ability to move, feed grow, reproduce and sense the world around them. Plants are another form of living thing, different from animals. Some things have never been alive; they have never been able to do what living things can do.
Living things die and cease to be able to do the things they could do while they were alive, All living things need to gain energy through nutrition in order to grow and reproduce. Plants share several characteristics of living things with animals; both grow and reproduce and require nutrition, but they perform these characteristics in different ways. Plants are not able to move or sense their environment in the same way as animals. Plants and animals are not the only forms of life on Earth. Animals and plants can be divided into smaller sub-groups according to their characteristics. The class of animal to which humans belong is the mammals.
Time and the degree of change from their living form are important factors in deciding whether an object was ohce alive or has never lived. As well as the living kingdoms of plants and animals, there are also fungi, micro-organisms without nuclei (such as bacteria), and simple-structured organisms with nuclei (such as algae), These kingdoms can be subdivided to a point where a species is defined as a set of living things that are able to reproduce viable young.